XRISM Confirms Fast Hot Wind Driving M82’s Outflow

For the first time, XRISM’s Resolve instrument directly measured the velocity of hot gas at the center of the starburst galaxy M82, finding speeds around 2 million mph (≈3 million km/h). The hot wind’s pressure from high temperatures appears capable of powering the cooler, galaxy-wide outflow, a result that challenges and refines models of starburst galaxies and the role of cosmic rays in driving galactic winds.